A series of radical new regulations for London's black cabs are to come into effect today in an attempt to clean up the capital's air and create a more sustainable clean transport infrastructure in the capital.

Mayor of London Ken Livingstone will today introduce the Taxi Emissions Strategy, under which London's 20,000 black taxis will be required to meet strict European emissions standards (Euro III) by 2007.

A flat rate fare of 20 pence per journey will be employed from April 2005 in order to cover the cost of converting black cabs to reach the new standards.

Commenting on the scheme, Mayor Livingstone said: "London has the worst air quality in the UK and air pollution is estimated to cause 1,600 premature deaths every year in London. For just 20p a journey we will see major health benefits for all Londoners.

"Taxi drivers are exposed to more pollution because they spend long hours on the road each day and tend to operate in the most polluted areas, such as central London and Heathrow, and the cab trade will also therefore be a major beneficiary of this policy.

"This is one of a number of measures I am putting in place to improve air quality in London. The central London congestion charge is already having an impact, with emissions in the zone cut by 12 per cent."

The taxis are set to be fitted with a series of clean air filters, particulate and NOx reduction devices in order to meet the new standards.

According to statistics, taxis are responsible for no less than 24 per cent of fine particle and 12 per cent of nitrogen oxide of road transport emissions in central London alone.